Draft gear for railway draft rigging



Nov. 25, 1958 A. E. DENTLER DRAFT GEAR FOR RAILWAY DRAFT RIGGING 3 Sheets-Sheet 1 Filed Dec. 50, 1954 A A A A A w w A .VA A mmmmmmfi.

' Nov. 25, 1958 A. E. DENTLER 2,861,696

DRAFT GEAR FOR RAILWAY DRAFT RIGGING Filed Dec. 50, 1954 5 Sheets-Sheet 2 Nov. 25, 1958 -A. E. DENTLER DRAFT GEAR FOR RAILWAY DRAFT RIGGING 3 Sheets-Sheet 3 Filed Dec. 30, 1954 2/ I I I 6..

Invent 0T .flrnoZdIIDeW/Zer 2,861,696 a DRAFT GEAR FOR RAILWAY DRAFT RIGGING Arnold E. Dentler, Oak Park, Ill., assignor to W. H. Miner, Inc., Chicago, 11]., a corporation of Delaware Application December 30, 1954, Serial No. 478,797

Claims. (Cl. 213-45) This invention relates to draft gear for railway draft rigging.

It is a main object of the invention to provide in a draft gear a resilient column having low initial resistance, which resistance increases at a gradually increasing rate as the column is compressed.

Another object of the invention is to provide a resilient column for draft gears composed of a plurality of groups of compressible units,-with the units in each group having characteristics in compression which are different from the characteristics of the units of the other group.

Another object of the invention is to provide in a resilient column as set out in the previous object, groups comprising several units, each of which units has the same characteristics in compression as the other units in that group.

Another object of the invention is to provide in a resilient column composed of aplurality of groups of units means associated with the group for limiting the amount of compression of the units of that group.

Another object of the invention is to provide a resilient column for draft gear capable of maintaining its characteristics in compression for a long period of time in the service for which it is intended.

Further objects of the invention not specifically mentioned here will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which Figure l is a plan view, partly in section, of the gear installed in the yoke and pocket of a vehicle;

Figure 2 is a front elevational view of the gear;

Figure 3 is a cross sectional view taken along a horizontal median plane through the gear showing it in its normal position;

Figure 4 is a fragmentary view similar to Figure 3, showing the gear at the end of the first stage of compression;

Figure 5 is a view similar to Figure 4, showing the gear under further compression;

Figure 6 is a view similar to gear completely compressed;

Figure 7 is a view similar to Figures 4 to 6, inclusive, showing a modified arrangement of units in the gear'in normal position; and c Figure 8 is a graph showing the operating characteristics of the gear. r

In draft gears for freight service, high capacity in foot pounds of work that the gear is capable of absorbing is a necessity. In such gears initial compression of 25,000 pounds or more is not unduly high and aids materially in achieving high capacity in the gear.

In draft gears for passenger service and cabooses entirely different conditions are encountered. Cabooses are relatively light, weighing in the range of 35,000 pounds, and with the long freight trains now common are sub- Figure 4, showing the jected to severe shocks due to run in and run out in 2,861,696 Patented Nov. 25, 1958 normal operation of a train over tracks having varying degrees of grade. Passenger cars vary greatly in weight from 100,000 to 120,000 pounds for light weight coaches up to 250,000 to 300,000 pounds for first class cars such as dome cars, lounge cars, diners, etc.-

Draft gears for passenger service and cabooses do not need as high maximum capacity in foot pounds of work as do freight gears, and must have a much lower initial resistance, say in the range of 10,000 to 15,000 pounds. Furthermore, increase in resistance in the gear should be gradual and free from sudden changes to more effectively cushion the vehicle against shocks resulting from normal operation of the train.

It is to theprovision of a gear for passenger service and cabooses that the present invention particularly relates. In its preferred form, the gear of the present invention is a self-contained device of such dimension as to enable the gear to be fitted into the standard pocket and yoke of a railway vehicle. A plunger projects from the device and also bears against a resilient column that consists of a plurality of compressible units divided into groups by suitable separating means. Each of the groups of units possesses characteristics in compression which are different from the characteristics of the units in the other groups although the individual units in each group all have the same characteristics in compression.

With arrangement of this kind the column can con veniently be made to have low initial resistance and as the gear is compressed from this starting point the increase in resistance is gradual and increases at a gradually increasing rate. The arrangement permits building into the gear maximum capacities of different amounts thereby to adapt the gear to the requirements of light weight cabooses and coaches and also to the heaviest passenger cars. Through this arrangement linear movement of the column through a distance great enough to insure maintenance of initial capacity, though there be changes in the dimensions of the yoke and pocket in which the gear is contained and in the characteristics of the column itself, can be achieved while initial compression is main tained at a desired low point. When forces acting upon the gear compress the column, resistance is built up gradually at a gradually increasing rate to maximum achieved when the plunger is completely telescoped into the device.

In its preferred form, the rubber column of the present invention consists of units each of which comprises a pair of metallic plates and a solid rubber pad interposed therebetween and bonded thereto. The pads in the various groups in the column are of difierent thicknesses thereby causing them to have difierent characteristics in compression. The individual pads in each group in the column are all of the same thickness and possess the same characteristics in compression. The separating means by which the column is divided into groups consist of aligners equipped with flanges disposed alongside of a group of units and engaging the casing, which flanges are of such dimension that they will engage the adjacent aligner after the units of that group have been compressed a predetermined amount. Through this arrangement none of the units in the column is loaded beyond the limit which extensive laboratory tests have determined that the unit can withstand without material change in its characteristics in compression. Long life of the gear underthe operating conditions to which it will be subjected is thus achieved.

As will be seen from the drawings, the gear of the present invention consists of a casing A which is of such dimension as to permit its insertion in the pocket B and yoke C of a railway vehicle. A plunger D projects from the front end of the casing and abuts against the front follower E which in turn engages the front lugs of the pocket and rear end of the coupler shank.

Within the casing are aplurality of groups of units F, G, H, and I, separated one group from the other by aligners J, K, and L, which function also to maintain the column aligned in the casing in known manner.

' The casingA is of rectangular cross section, tthereby to utilize a maximum amount of space in the pocket,'-and contains flanges inturned at its open end .to provide stops for limiting the outward movement of the..plung g er D. The rearendll of thecasing consistspfa removable wall of known construction, having-flanges 12 which engage inturned flanges 13 ontthe top and bottom of the casing to hold the assembly. together. A

In the embodiment shown the dr awings, in.group F, a single resilient unit consists Zofa solid rubber pad ii disposed betweenand bonded to a.front plate Manda rear plate 17 in known manner. The edges of the rub ber pad are formed concavely as shown, to provide how space into .which the rubber may moveas the pa d is compressed. The units in group G consist of rubber pads 20disposed between and bondedtometal. plates in the same manner. -It will be noted that each of the three pads 20 in this group is thinner, than the .pad 15 in the group F. Similarly, the units .of groupI-I contain .pads 21 disposed between and bonded to a pair of metallic plates and having thickness less than the thickness of .pads 20. The units in. group I contain rubber pads 22 also disposed between and bonded to metallic plates, which pads22 are thinner than the pads 21 of group H.

The plunger D contains arearwardly extending flange disposed alongside of the pad 15 and having height such that'it will engage the aligner I after the pad 15 has beencompressed a relatively short distance. Aligner J is equipped with a rearwardly extending flange 31 disposed alongside of the pads 20 in group G, which flange 31 is likewise adapted to engage aligner K after the pads in group G have been compressed a predetermined amount. Aligner K is equipped with a rearwardly extending flange 32, which also is of such height as to engage aligner L after the pads in group H have been compressed a predetermined amount. Aligner L has a short flange 33 extending forwardly to be engaged by the flange 32. Aligner L does not have any appreciable rearwardly extending flange.

Located betweenthe units in group I and the rear .wall 11 of the casing is a rear follower 34 which has a forwardly extending flange 35 containing perforations 36 adapted to be registered with perforations 37 as the column is compressed, thereby topermit insertion of keys which hold the follower 34 forwardly thereby to permit placing the rear wall 11 in the casing in known manner. 7

In Figt ire;3, the geariis "shoiwnin normal position in the yoke and -p ockeh as shown in Figure 1. Since the distance betweeri the lugs th a t define the rear, end of the pocketand the rear face of the front follower E is less than the, overall-,length pf the gear, with the plunger D extended sufliciently toengage the flanges 30 thereon with the flanges 10 on the casingtwhen the gear is positioned inthe pocket, the plunger D is moved inwardly of the easing into the positionshown in Figure 3. Thus, it will be seen that engagementof theplunger D with the front follower E maintains the initial compression of the column.

In Figure 4, the gear is shown inthepositionit assumed at the end of the firststa ge of compression by forcesactingupon thecolumn. Blunger D has moved rearwardly against the relatively lowresistance of pad is and the flange 30 on theplungerhasengaged the flange 31 on aligner J, thereby to limit'the compression of pad 15. The column, having an initial low resistance, has thus had built up in'it a slight increase in resistance which, of course, is transmitted throughout the groups of units inthe column; that is to say, during movement of the plunger from :the, position shown in Figure 3 to the position shown in .Figure 4, aligners I ,K, and L will have moved towards. thelrear end ofthe .casingalthough this shown in Figures 3 to 6, inclusive. with curve 40 to the left of point-41, thereby retaining movement will be substantially less than the movement of the plunger.

In Figure 5, I have shown the column still further compressed, although not sufficiently to move flange 31 on aligner J into engagement with aligner K. It will be noted that the plunger D still projects a substantial distance out of the casing A.

In Figure 6, the plunger D has moved into the casing until it is. flush therewith. Flange30 engages aligner l, flange 31 engages aligner K, and flange 32 engages the flange 33 on aligner L. Thus, the compression of the units in group F, G, and H has reached its maximum and the pads in groupLhave. likewise been compressed as much as possible, since the forward end of the plunger D is aligned with the end of the casing. It will be noted that flange 35 on the rear follower is still spaced from'the aligner L.

From the foregoing, it will be apparent that each group of units in the column resists compression of the column through a part of the movement of the plunger and that when thejload on a group of units equals a predetermined maximum, that group is not subject to further loading. During the initial travel of the plunger, all of the groups of units in the column resist that travel, and at the end of the plunger movement inwardly of the gear but one group of units resists the plunger. This latter group ofunits cannot be overloaded since alignment of the plunger with the end of the gear casing renders impossible further compressing of the units.

Through this arrangement each unit in the column is loaded to a maximum well within safe limit that that unit is capable of withstanding without damage. Overloading of a unit is definitely prevented regardless of the position in thecolumn of that particular unit. This protection of the units comprising the column insures that the gear willhave long life in the service for which it is intended.

The performance of the gear is. graphically illustrated in Figure 8. Curve 40 illustrates the resistance which would be encountered in a gear composed solely of low resistance units such as F. Starting at point 4 1, at which the plunger is in the positionshown in Figure 3, curve 40 slopes gradually in both directions, that portion of the curve to the left-of the point 41 representing the lineal movement of the column in building up resistance therein from zero at 42 to the initial resistance at point 41, which is an initial resistance in the range of 10,000 to 15,000 pounds. Movement to the right of point 41 is the normal travel of ther plunger in operation and as the column of low resistance units is compressed the resistance of the column increases but slightly. Since the area under the curve 40 representsthe amount of work that the gear is capable of absorbing, it will be seen that the gear that the curve represents would have a capacity entirely too low to be satisfactory under present day conditions.

Curve 43 represents the increase in resistance of .a column composed entirely of high resistance units. It will be noted that the slope of curve43 is greater than that of curve 40, with the result that very little linear movement of the column, represented by that portion of curve 43 to the left of point 41 from zero point 44 to point 41 isnecessary to ,build up in the column the desired low initial resistance. The curve 43 rises rapidly and as a result the-workthat such a gear would be able to absorb is greater; however, the margin of safety is entirelytoo small andslight changes. in thedimens ions of the pocket and yoke, or characteristics of :the resilient material in the column, wo uld wipeoutthis reserve and unwanted slack in the gear would then result.

Curve 45 represents theperformance of the column Curve 43 coincides the-safety factor of large lineal movement necessary to buildup :jnthe column thedesired residual or initial resistance. ,As thevariousgroups of units in the column are compressed and blocked, resistance thus built up in the column increases gradually at a gradually increasing rate, the resistance is less than that for the gear represented by curve 43, but is ample in the service for which the gear of the present invention is intended. The substantial area under curve 45 indicates a substantial ability to resist foot pounds of energy placed on the gear in normal service.

In Figures 3 to 6, inclusive, the groups of units F, G, H, and I are arranged with the low resistance group F adjacent the plunger and the highest resistance group I adjacent the rear of the casing. It is not necessary that this arrangement of units in the column be maintained. In Figure 7, I have shown an alternate arrangement wherein the pad of group F is adjacent the plunger as before, group H is moved ahead of group G, and group I remains adjacent the rear of the casing as before. The flanges on the separators J, K, and L are modified so as to limit the compression of the various groups in the same manner as before.

From the foregoing it will be apparent that a column in which compressible units are arranged in groups, with the units in each group having characteristics in compression different from those of other groups, permits building into a gear particular operating characteristics wherein the resistance increases from a relatively low initial resistance at a gradually increasing rate. The provision of flanges on the separators that define the groups guards against overloading the compressible units in the associated group, thereby insuring long service of those units.

While I have chosen to illustrate my invention by showing and describing a preferred embodiment of it, I have done so by way of example only, as there are many modifications and adaptations which can be made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

I claim:

1. In a draft gear for railway draft rigging; a resilient column composed of a plurality of units; aligners dividing the units into groups, each of said units comprising a pair of metal plates with a solid rubber pad interposed therebetween and bonded thereto, the pad in each unit in each group having the same resistance to compression as the other pads in that group, which resistance is diflferent from the resistance of the pads in the other groups; and flanges on said aligners disposed alongside of the units of a group and adapted to engage the adjacent aligner, thereby to limit the compression of the units in the group by forces acting upon the column.

2. A resilient column as specified in claim 1, in which the variation in resistance to compression is achieved by variation in the thicknesses of the pads in the several groups.

3. A resilient column as specified in claim 1, in which the pads in one group are thicker than the pads in the other groups to provide maximum compression of said one group of units in response to low compressive forces acting upon the column.

4. A resilient column as specified in claim 1, in which the pads in one group are thinner than the pads in the other groups to provide minimum compression of said one group of units in response to maximum forces acting upon the column.

5. In a unitary draft gear for railway draft rigging, a casing open at one end and closed at the other end; a pressure applying plunger telescoped in said casing and projecting through said open end; a resilient column within said casing bearing against said plunger and the closed end of the casing, said column being composed of a plurality of units with each unit consisting of a pair of metal plates and a solid rubber pad interposed therebetween and bonded thereto; aligners dividing said units into groups, the pad in each unit in each group having the same thickness axially of the column as the other pads in that group, which thickness is different from the thicknesses of the pads in the other groups; and flanges on said aligners each extending alongside a group of units, said flanges being moved into engagement with the adjacent aligner upon compression of the group of units alongside of which the flanges are disposed, thereby to limit the compression of the units in that group by forces acting upon said plunger.

References Cited in the file of this patent UNITED STATES PATENTS 1,853,857 Glascodine et a1 Apr. 12, 1932 2,051,864 Knox et a1. Aug. 25, 1936 2,066,187 Piron Dec. 29, 1936 2,639,044 Mulcahy May 19, 1953 2,713,483 Tillou July 19, 1955 

